1. Field
The following description relates to a power supply apparatus supplying power to a power amplifier used for wireless communications.
2. Description of Related Art
Wireless communications schemes allowing large amounts of information to be transmitted have recently become more commonplace. The characteristics of wireless transmission signals currently used in wireless communications and intended for use in the future have a wide band and a high peak to average power ratio.
Accordingly, signal bandwidths are increased. In order to improve overall efficiency of systems in such environments, the consumption of direct current power by power amplifiers is beneficially reduced.
However, when power amplifiers are generally designed, there exists a disadvantage in that the power amplifier is reduced from a maximum power point by several dB, in order to secure linearity. This results in the reduction of overall efficiency of the system because efficiency is decreased at lower power settings.
Previous attempts to address such issues, such as by an envelope tracking method may be problematic, in that a signal bandwidth which is processed is not significantly wide, and such a circuit and a configuration are relatively complex, even if wide bandwidth signals are processed.